Sofa



FIG. 1 is a perspective view of a sofa, showing my new design;

FIG. 2 is a front elevational view of the invention, the rear elevational view being identical thereto;

FIG. 3 is a left-side elevational view of the invention, the right-side elevational view being identical thereto;

FIG. 4 is a top plan view of the invention; and,

FIG. 5 is a bottom plan view of the invention. 

I claim the ornamental design for sofa, as shown and described. 